Australia, Postage Due, 1936, 6d carmine & yellow green, perf 11, irregular block of 3, tied by "Fremantle, 1 Je, 37" cds's on incoming airmail cover, franked with G.B. 6d KGV tied by "Scarborough, Yorks, 9 May, 1917" machine postmark, blue crayon "45" in circle and "T" in octagon handstamp, bold Fremantle receiving cds and reverse with Perth transit backstamp, Very Fine. Scott No. J62. SG No. D110  Estimate $4,000 - 6,000. A REMARKABLE LARGEST RECORDED USED MULTIPLE OF THE SCARCE 1936 6D PERF 11 POSTAGE DUE ISSUE. CONSIDERED THE RAREST COVER OF THE AUSTRALIAN COMMONWEALTH PERIOD. While the airmail rate from Australia was 1/6 per half ounce, the rate from England was only 1/3. This equivalent deficiency of 9d is reflected as 9d postage plus 9d tax. The small blue crayon 45 refers to the 45 gold centimes (UPU artificial international currency) for which the A£ equivalent was 1/6. $0 (Image)